Ship-deck planking



April 9, 1946.

A. A. GLIDDEN x-:TAL

SHIP-:DECKr PLANKING Filed Sept. 22, 1942 badly and the splintered wood often ignites and Patented Apr. 9, 1946 i slur-DECK PLANKING Alfred A. Glidden, Watertown, and Walter R. Hickler, Winthrop, Mass., asslxnors to The B. F; Goodrich Company, New York, N. Y., a corporation of New York Application september 22, 1942, serial No. 459.270

' s claims. (ci. isi- 45m This invention relates to ship-deck planking and similar board or lumber material.

Weather decks of shipsas usually constructed include steel deck plates over which are mounte ed wood planks. Teak wood has long been considered the most desirable deck-planking material although other woods such as long leaf yellow pine and white oak have been used, `even though inferior to teak in some respects, because of the higher cost and relative scarcity of teakv wood. Because of the turbulent international situation, it is now especially diillcult to obtain sufiicient quantities of teak wood from the tropical regions where it grows.

Furthermore, all such wood planking heretofore used for decks has been subject to a number of disadvantages, especially for use on. ships subject to attack. in war times. When struck by shells or bombs, natural wood planking splinters burns freely. Even unsplintered teak wood` is l burned by incendiary bombs. Also, natural wood planking absorbs water to a greater or lesser degree and consequently is subject to shrinking and swelling so that caulking between theplanks is often loosened, thus permitting sea water to come in contact with the steel plates underneath and cause corrosion. The latter problem is aggravated by the fact that teak Wood, because of` its nature, is obtainable only in the form of rel-l atively narrow planks not more than four or five inches wide, `so that many caulked seams are necessary.v

The present invention aimsto provide shipdeck planking comprising synthetic board material substantially free of all the foregoing objections inherent in natural wood planking and, in addition, exhibiting several outstanding superiorities over natural wood planking. The manner in which this aim is accomplished will appear fromthe following detailed description of the invention in a preferred embodiment as illustrated in the vaccompanying drawing.

Of the drawing, g

Fig. 1 is a conventionalized fragmentary perspective view of the forward portion of a War shipl provided with deck-planking made in accordance with the present invention.

Fig. 2 is a fragmentary perspective view illustrating a preferred type of fibrous material utilized in making the present ship-deck planking.

Fig. 3 is a diagrammatic side elevation illustrating steps in the manufacture of theA shipdecking material and more particularly showing the steps of saturating the fibrous material of Fig. 2 with resinous or other binder material.

Fig. 4 is a diagrammatic vertical cross-sectional view illustrating the step of molding the treated fibrous material ,to produce ship-deck plank- Fig. 5 is a fragmentary perspective view showing a finished piece of ship-deck planking emboclyins the invention.

In manufacturing ship-deck planking in accordance with a preferredembodiment of our invention', .we rst prepares. mass of relatively coarse, resilient vegetable or other fibersl I 0 arranged in helter-skelter fashion in compact sheet form. A variety of coarse, resilient and relativey 1y long lbersrnay be utilizedl for this purpose including preferably the hard or vascular bers such as sisal, abaca, henequen, henequen bagasse,

cautela, Phormium, Piteira, istie, palma, pita floja, pine, pineapple and coconut, sisal fibers being especially satisfactory for general use. The crude bers should be combed out into lengths and then arranged in helter-skelter fashion in f the fonn of a web or sheet of such weight as to be handled conveniently, usually about 15 to 20 oz. or sometimes as high as 30 oz, per square Yard..

For reasons,` hereinafter more fully explained,

it is preferred next to apply to one or both faces. ofthe sheet of coarse fibers I0 a thin tenuous web li of finer and less-resilient fibers. Thus,

the web Il preferably comprises cotton fibers but may be formed of other soi't fibers such as flax, ramie, wool, silk, rayon, nylon and the like. The soft fiberspreferably, although not necessarily, are carded and thereafter drawn out to form a thin web'weighing from about 0.3 oz. to about 1 `oz. per square yard, the fibers in the web bing arranged in parallel relation.

tenuous web I I is pre-treated with resin or other binder material compatible with, and preferably although not necessarily of the same character as, that to be used in saturating the composite fibrous structure as hereinafter described.

' which preferably should be a liquid composition comprising a heat-setting resin. An alcohol so- After being'thoroughlysaturated and impreg- The prepared fibrous structure as shown in Fig. 2 is then desirably compacted as by passage between presser rolls I2-I2 after which the sheet is passed thro-ugh a bath of binder material i3 lution of-a phenol-formaldehyde resin in an unpolymerized stage is very satisfactory although vwater dispersions of resins may also be used.

nated with the resin, the fibrous material is passed through a, conventional hot air oven or other heating meansr Il where all the alcohol or other solvent is dried from the material and the Deslrably, the

lresin preferably is partially, but not completely. polymerized, the polymerization being carried only to a point where the resin will temporarily plasticize under further heat and pressure.

To assist in handling the fibrous sheet during the saturating and drying operations, sheets of paper may be placed on either face thereof and fed through the operations along with the fibrous sheet. Also, the fibrous sheet may be needleloomed, preferably only lightly and only sunlciently to hold the sheet together while it is being handled. Needle-loomed webs of sisal fibers of the required 15 to 20 or 30 ounce per square yard Weights are available commercially and may be used quite satisfactorily. It has been found, however, that needle-looming of the fibers prevents, to some extent, the desired even penetration and saturation of the fibrous structure with resin. This condition is greatly improved by utilizing surface webs of tenuous cotton fibers treated with resin as hereinabove described, the tenuous webs being applied to the fibrous sheet prior to the needle-loomingoperation so that the resin treated cotton fibers are carried transversely through the fibrous sheet by the needles, thus providing firm adhesive contact with the coarse fibers constituting the main portion of the sheet.

An appropriate quantity of the resin-treated A fibrous material then is placed in the cavity of any suitable heat-molding device and subjected to heat and pressure to integrate the structure and complete polymerization of the resin to a hard stage. A suitable mold is illustrated diagrammatically in Fig. 4 asl comprising a lower steam-heated platen l5 provided with a cavity of the proper shape and an upper steam-heated platen I6 adapted to function as a cover plate for the mold.

The molding conditions, of course, will vary somewhat depending upon the particular resin chosen, but in a typical example utilizing a phenol formaldehyde resin, pressure sufcient to close the mold and thus produce the desired volume is applied, this requiring about 100 lbs./sq. in. in a typical case. Such pressure is maintained and a temperature of about 300 F. is applied for a time sufll-l cient to integrate lthe material and harden the resin, a period of about three hours being necessary fora deck plank such as a 3 in. thick board.

' Thereafter, the material is cooled while the pressure is maintained and, finally, the finished board d is removed from the mold.

described having a specific gravity of 0.96 exhibits low heat conductivity comparable to that of white oak and teak wood, a characteristic not heretofore obtained in any synthetic planking material.

In order to produce material of the desired specific gravity the volume of the mold cavity should be determined and an appropriate weight of the Usually, the mold cavity will be shaped to produce a finished board having the configuration of the board I1 shown in Fig. 5, the opposed longitudinal edges on one face of the board being substantially bevelled as shown at I8, I8 so that adjacent boards Will mate together to form caulking grooves. Also, recessed apertures I9 should be provided in the boards for receiving bolts or other deck attaching means customarily employed for fastening the planks to the steel deck plates. 'I'hese recessed apertures may be molded in the boards or they may be machined in them after the molding operation is completed.

In order to secure satisfactory physical characteristics in the planking and especially to secure satisfactorily low heat-conducting properties, we have found that it is highly important to control the specific gravity of the planking materialwithin close limits. Satisfactory properties are secured when the specific gravity is not lower than 0.7 nor higher than 1.1. Best results are attained actual use. Ship-deck planking of the haracter when the specific gravity ranges from 0.9 to 1.0, a c specific gravity of 0.96 having been adopted for resin-treated fibrous material loaded in the mold to produce material of the proper density.

Planking made in accordance with the invention may be laid in the same manner as natural wood planking on the weather-deck D of a warship S or other ship, boat or similar craft.

A typical ship-deck plank embodying sisal fibers and phenol formaldehyde resin and having a specinc gravity of approximately 0.96'has been shown by actual test not only to be free of the objections inherent in natural wood planking as hereinabove described but also to exhibit outstanding superiorities over natural wood in many respects. The present material has been shown to outwear teak wood as much as 21/2 times. In hardness and compressive strength it is definitely superior to teak wood. Its thermal conductivity is comparable to that of teak wood and white oak and in a specific vcomparison was found to be exactly the same as a I particular sample of white oak. Exemplary samples of the present artificial planking exhibit a tensile strength of over 10,000 lbs./sq. in. and a block compression strength of over 20,000 lbs/sq. in. The planks may be sawed, planed, drilled, bored, threaded, and generally worked in the same manner as wood. Whereas natural wood .planking burns readily under favorable conditions, the present planking does not burn when subjected to a hot flame but merely chars. The present planking does not splinter as'does natural wood when hit by explosive bombs or shells. Also, it has an extremely low water absorption and consequently is not subject to shrinking and swelling so that it retains caulking much better than does natural wood. The synthetic materialmay be molded in the form of planks many times as wide as the widest practically available in teak wood, with consequent great reduction in the number of individual planks required to cover a given'deck area. As a result, the number of caulked seams and troubles incident thereto. are reduced to a fraction of the number formerly met, the number of attaching bolts is similarly reduced, and the overall labor and expense of installation and maintenance is cut to a fraction of the former cost.

The presence of the tenuous cotton or other soft fiber webs on either face of the body of coarse fibers, and contiguous to the surface of the molded planks, assists materially in providing at the surface the qualities Aof toughness, wear-resistance and freedom from splintering exhibited by the present material.

Although the heat-setting resins should be vused for ship planking, it is possible in other material interspersed therethrough, said brous material comprising coarse, resilient vegetable fibers of the hard or vascular type arranged in unwoven heiter-skelter fashion but with substantial uniformity through the resin, said board lhaving a speciilc gravity of from 0.7 to 1.1. heat conductivity comparable to that of teak wood, hardness substantially greater than teak wood, compressive strength at least equal to teak wood, and abrasive wear characteristics substantially exceeding teak wood, said synthetic lumber including at a surface thereof an embedded web or thin sheet of fibers which are relatively line and less resilient than the coarse resilient vascular fibers.

2. Synthetic lumber as defined by claim 1 in which the hard or vascular bers are sisal ilbers and in which the surface embedded web or thin sheet comprises cotton fibers.

3. A composite product comprising a mass of sisal bers in heiter-skelter arrangement, a web oi' cotton fibers needle loomed therewith, and resin material substantially permeating the entire fibrous mass,

4. A composite product comprising a mass of relatively coarse resilient bers in helter-skelter arrangement, a web of relatively iine bers on a face of said mass, portions of said web extending into said mass, and a body of resin material substantially permeating the entire fibrous mass.

5. A composite product comprising a mass of relatively coarse resilient fibers in helter-skelter arrangement, a web of parallel cotton fibers on a face of said mass, portions of said cotton fiberI web extending into said mass, and a continuous uninterrupted body of heat-set resin material uniformly permeating the entire brous mass in a uniform manner.

ALFRED A. GLIDDEN. WALTER R. HICKLER. 

